spreadsheets.ppt

© Boardworks Ltd 20041 of 19

Spreadsheets

Software

This icon indicates that detailed teacher’s notes are available in the Notes Page.

For more detailed instructions, see the Getting Started presentation.

This icon indicates the slide contains activities created in Flash. These activities are not editable.


Spreadsheets can:

do all sorts of calculations, both simple and complex, using formulae

use functions to help you set up complex formulae

act as simple databases so that you can sort or search your data

plot charts and graphs

change the appearance of fonts, cell backgrounds and borders

control how many decimal places are shown.

What does the software do?


Basic features


What else can it do?

look up data from lists

do specialized calculations in subjects like finance, statistics and trigonometry

experiment with questions, such as “What if the interest rate went up by 1%?”

use logic such as IF, AND and OR

change the format of a cell depending on what is in it (conditional formatting)

use pivot tables to summarize data

reduce the number of input errors by setting rules (validation).

Functions can help the user to:


Can I have a go?


Spreadsheets also include some features you would expect to see in a database. An example of this is the lookup function.

Like a database, the table has:field names – Subject, Teacher, Room records – each row is a different record. For example, record 1 is “English Mrs Ridyard Room A”.

Lookup table

This function allows you to search through a table of information and find the relative value – which is why it is called a lookup table.


To find out the ICT teacher, you would look down the Subject column until you found ICT, then across to the Teacher column to find the teacher’s name.


The computer does just the same. Let’s look at the function which is entered in cell B7:

=VLOOKUP(A7, A2:C5,2) – Mrs Spencer

Vertical (i.e. column)

lookup (find)

Find the word in cell A7

Look between A2:C5

Take the value in

column 2


To find the room that ICT is in, you would put the following lookup function in cell C7:

=VLOOKUP(A7, A2:C5,3)

The answer is 8.

Vertical (i.e. column)

lookup (find)

Find the word in cell A7

Look between A2:C5

Take the value in

column 3


Goal seek

Another very useful feature of spreadsheets is goal seek. This can speed up certain calculations.

You can take the £10.00 profit required, add it to the cost, and then divide the total by the number of eggs.

For example, a shop has a box of 50 Easter eggs which they want to sell very quickly as Easter is today. They want to reduce the price and just make a profit of £10. How do they find out the price the eggs have to be sold for?


Or you can use goal seek.

Price changes to £1.71

Profit changes to £10.00

You want to change the profit (cell D6) to £10 by changing the price of each Easter egg (cell C4).


How would you find out what price the eggs need to be to make a £5 profit?

How would you find out what price the eggs would need to be sold for to make a £24 profit if they came in boxes of 55?How would you find out how much the eggs must be sold for so the shop can make a profit of £24 if the cost of each box goes up to £80?


What would it be used for?


If 24 people are waiting

Goal seek

and 3 checkouts are open

they wait 16 minutes.


Goal seek can work out how many checkouts are neededto cut queuing time to 8 minutes.

Change the waiting time

to eight minutes

by changing the number

of checkouts.


We need 6 checkouts open to keep waiting time down to 8 minutes.


Who would use it?

Spreadsheets are used by:

engineers to test whether structures are strong enough

business managers to model their finances

scientists to simulate (work out) what might happen in different circumstances

teachers to calculate marks and grades.


Summary

Spreadsheet software is mostly used for simple and complex calculations using formulae.

Spreadsheets are also very useful for plotting charts.

They can be used to sort and search data.

Functions make it easier to set up complicated calculations.

Vlookup looks things up in lists.

Spreadsheet simulations can model situations so that you can ask “What if” questions.

spreadsheets.ppt

Documents